JP6658031B2 - Resin composition, electrostatic image developing toner, electrostatic image developer, toner cartridge, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to a resin composition, a toner for developing an electrostatic image, an electrostatic image developer, a toner cartridge, a process cartridge, an image forming apparatus, and an image forming method.

  In image formation by the electrophotographic method, a light fixing method of performing fixing by applying light to an unfixed toner image formed on a recording medium is known, and as a toner used for image formation of the light fixing method, Toners containing infrared absorbers are known.

For example, Patent Literature 1 discloses a color toner for flash fixing, which is provided around a core containing a colorant in a binder resin by thermally melting a coating portion containing an infrared absorber in the same resin as the resin. Is disclosed.
Japanese Patent Application Laid-Open No. H11-163873 discloses a transfer member on which the toner image is transferred by using a toner in which an infrared absorber is coagulated and dispersed in a binder resin and the light absorption of a laser beam having a specific wavelength decreases after the toner is melted. A laser fixing method for irradiating a laser beam of the specific wavelength to fix a toner image on the transfer-receiving member is disclosed.
Patent Document 3 discloses an electrophotographic toner containing a binder resin and an infrared absorber, wherein at least one of the infrared absorbers is a perimidine-based squarylium dye.

Patent Document 4 discloses a resin composition and an image forming material containing a perylium-based squarylium compound having a specific structure.
Patent Document 5 discloses a croconium compound having a specific structure.
Patent Document 6 discloses a dye composed of an inner salt of a squarylium compound having a specific structure.
JP-A-02-118670 JP 2014-153621 A JP 2010-186014 A JP 2013-147595 A JP 2007-169315 A Japanese Patent Publication No. 05-505641

Conventionally, for the purpose of imparting infrared absorption performance to the resin composition, it has been tried to include a squarylium-based compound or a croconium-based compound. (Color turbidity may occur).
The object of the present invention is selected from the group consisting of a compound represented by the following general formula (I-1), a compound represented by the general formula (I-2), and a compound represented by the general formula (I-3). An object of the present invention is to provide a resin composition in which color turbidity is suppressed as compared with a case where only one compound is contained.

The above problem is solved by the following means. That is,
The invention according to [ 1 ] ,
Resin and
At least one selected from the group consisting of compounds represented by the following general formula (I-1),
At least one selected from the group consisting of a compound represented by the following general formula (I-2) and a compound represented by the following general formula (I-3),
A resin composition comprising:

(In the general formula (I-1), the general formula (I-2) and the general formula (I-3), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ each independently represent hydrogen, an alkyl group, an alkoxy group, an aryl group, or an aralkyl group, R ¹⁵ , R ¹⁶ , R ²⁵ , R ²⁶ , R ³⁵ , And R ³⁶ each independently represent hydrogen or an alkyl group, X represents oxygen, sulfur, selenium, or tellurium, a plurality of Xs represent the same element, and Y represents oxygen, sulfur, selenium. Or tellurium, and represents an element different from X, and a plurality of Y represents the same element, wherein A ¹ , A ² , and A ³ are each independently the general formula (a1) or the general formula (a1); Represents a divalent group represented by the formula (a2). A divalent group represented by (a1) or the general formula (a2) is attached at *.)

The invention according to [ 2 ] ,
The formula (I-1), wherein in the formula (I-2) and the general formula (I-3) X represents one of oxygen and sulfur, wherein Y represents the other oxygen and sulfur [1] The resin composition as described in the above.

The invention according to [ 3 ] ,
Among the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3), the compound represented by the general formula (I-1) [ 1 ] or [ 2 ] , wherein the proportion of the compound represented by the formula (I) or the proportion of the compound represented by the formula (I-2) is from 85.0 mass% to 99.9 mass% . The resin composition as described in the above.

The invention according to [ 4 ] ,
A toner for developing an electrostatic image, comprising the resin composition according to any one of [ 1 ] to [ 3 ] .

The invention according to [ 5 ] ,
An electrostatic image developer comprising the electrostatic image developing toner according to [ 4 ] .

The invention according to [ 6 ] ,
Containing the toner for developing an electrostatic image according to [ 4 ] ;
A toner cartridge that is attached to and detached from an image forming apparatus.

The invention according to [ 7 ] ,
And a developing unit for storing the electrostatic image developer according to [ 5 ], and developing the electrostatic image formed on the surface of the image holding member as a toner image by the electrostatic image developer,
A process cartridge that is attached to and detached from the image forming apparatus.

The invention according to [ 8 ] ,
An image carrier,
Charging means for charging the surface of the image holding member,
Electrostatic image forming means for forming an electrostatic image on the surface of the charged image carrier,
A developing unit that contains the electrostatic image developer according to [ 5 ], and develops the electrostatic image formed on the surface of the image holding member as a toner image with the electrostatic image developer;
Transfer means for transferring the toner image formed on the surface of the image carrier to the surface of the recording medium,
Fixing means for fixing the toner image transferred to the surface of the recording medium,
An image forming apparatus comprising:

The invention according to [ 9 ] ,
A charging step of charging the surface of the image carrier,
An electrostatic image forming step of forming an electrostatic image on the surface of the charged image carrier,
A developing step of developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer according to [ 5 ] ;
A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium,
Fixing step of fixing the toner image transferred to the surface of the recording medium,
An image forming method comprising:

According to the invention according to [ 1 ] or [ 2 ] , the compound represented by the general formula (I-1), the compound represented by the general formula (I-2) and the compound represented by the general formula (I-3) The present invention provides a resin composition in which color turbidity is suppressed as compared to a case where only one compound selected from the group consisting of the compounds represented by the formula is contained.

According to the invention according to [ 3 ] , the compound represented by the general formula (I-1), the compound represented by the general formula (I-2) and the compound represented by the general formula (I-3) Among them, both the ratio occupied by the compound represented by the general formula (I-1) and the ratio occupied by the compound represented by the general formula (I-2) exceed 99.9% by mass, A resin composition in which color turbidity is suppressed is provided.

According to the invention according to [ 4 ] , [ 5 ] , or [ 6 ] , the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I) -3) a toner for developing an electrostatic image, an electrostatic image developer in which color turbidity is suppressed as compared with a case where only a resin composition containing only one compound selected from the group consisting of the compounds represented by the following formula: Alternatively, a toner cartridge is provided.

According to the invention according to [ 7 ] , [ 8 ] or [ 9 ] , the compound represented by the general formula (I-1), the compound represented by the general formula (I-2) and the compound represented by the general formula (I) Process cartridge in which color turbidity of a toner image is suppressed as compared with a case where an electrostatic image developing toner containing only a resin composition containing only one compound selected from the group consisting of compounds represented by -3) is used. , An image forming apparatus, and an image forming method are provided.

FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment.

  Hereinafter, the present embodiment, which is an example of the present invention, will be described.

<Resin composition>
The resin composition according to the present embodiment includes the following components.
(1) Resin
(2) at least one selected from the group consisting of compounds represented by the following general formula (I-1)
(3) at least one selected from the group consisting of a compound represented by the following general formula (I-2) and a compound represented by the following general formula (I-3)

In the general formulas (I-1), (I-2) and (I-3), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ each independently represent hydrogen, an alkyl group, an alkoxy group, an aryl group, or an aralkyl group.
R ¹⁵ , R ¹⁶ , R ²⁵ , R ²⁶ , R ³⁵ , and R ³⁶ each independently represent hydrogen or an alkyl group.
X represents oxygen, sulfur, selenium, or tellurium, and a plurality of Xs represent the same element.
Y represents oxygen, sulfur, selenium, or tellurium, represents an element different from X, and a plurality of Y represent the same element.
A ¹ , A ² , and A ³ each independently represent a divalent group represented by Formula (a1) or Formula (a2).
In addition, the divalent group represented by the general formula (a1) or the general formula (a2) bonds at the position of *.

According to the resin composition according to the present embodiment, by providing the above-described configuration, a resin composition in which color turbidity is suppressed is provided.
The reason for this effect is not clear, but is presumed as follows.

  Conventionally, squarylium-based compounds (for example, a compound in which A is the general formula (a1) among the compounds represented by the following formula (base)) for the purpose of imparting infrared absorption performance to the resin composition, And a croconium-based compound (for example, a compound represented by the following formula (base) wherein A is the general formula (a2)) and the like. However, since squarylium-based compounds and croconium-based compounds also have absorption wavelengths in the visible region, the presence of these compounds may cause the resin composition to become colored and turbid. Therefore, it is required to suppress the occurrence of color turbidity.

(In the formula (base), R ¹ has the same meaning as R ¹¹ , R ^21, and R ^{31 in the} general formulas (I-1) to (I-3), and R ^{2 to} R ⁴ are also the same as those in the general formula (I-3). is as defined for formula (I-1) to ^{R 12} to ^R 14 in the ^{(I-3), R 22} to ^{R 24,} and ^{R 32} to ^{R 34.}
R ⁵ and R ⁶ have the same meanings as R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , and R ^{35 to} R ^{36 in the} formulas (I-1) to (I-3), respectively.
A has the same meaning as A ^{1 to} A ³ in formulas (I-1) to (I-3).
Z represents oxygen, sulfur, selenium, or tellurium, and a plurality of Zs may be the same or different. )

  On the other hand, the resin composition according to the present embodiment includes at least one selected from the group consisting of the compound represented by the general formula (I-1) and the compound represented by the general formula (I-2). And a compound represented by formula (I-3) and at least one selected from the group consisting of compounds represented by formula (I-3). That is, it is a mixed system in which at least one element of the plurality of “Z” in the formula (base) contains two or more compounds different from each other.

Since at least one of Zs in the formula (base) is a mixed system containing two or more different compounds, compared with a pure substance system containing only one compound represented by the formula (base), It is considered that the dispersibility in the composition is improved.
In a pure substance-based embodiment containing only one compound represented by the formula (base), the compound easily forms a crystal and is strongly bound to each other, so that an aggregate is easily generated. On the other hand, in a mixed system mode in which at least one of Zs in the formula (base) contains two or more compounds, the binding between the compounds is weakened, the generation of aggregates can be suppressed, and the generated aggregates can be suppressed. Can also be smaller. As a result, the dispersibility in the resin composition is improved, and characteristics such as infrared absorption performance are sufficiently exhibited. Therefore, the amount of the compound represented by the formula (base) can be reduced. It is considered that the reduction in the amount of addition reduces the tint of the resin composition and suppresses color turbidity.

  Hereinafter, the configuration of the resin composition according to the present embodiment will be described.

(Specific squarylium-croconium compounds)
The resin composition according to this embodiment includes a compound represented by the following general formula (I-1), a compound represented by the following general formula (I-2), and a compound represented by the following general formula (I-3) (In the present specification, these are collectively referred to as “specific squarylium-croconium-based compounds”.)
(2) at least one selected from the group consisting of compounds represented by the following general formula (I-1)
(3) at least one selected from the group consisting of a compound represented by the following general formula (I-2) and a compound represented by the following general formula (I-3). The mixture with (3) is referred to as "specific squarylium-croconium compound mixture".

· ^{R 11} to ^{R 14, R 21} through ^{R 24,} and ^{R 31} to ^{R 34}
In the general formulas (I-1), (I-2) and (I-3), R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ each independently represent hydrogen. , An alkyl group, an alkoxy group, an aryl group, or an aralkyl group.
In addition, it is preferable that it does not have an unsaturated bond from a viewpoint of suppression of color turbidity, an alkyl group or an alkoxy group is preferable, and an alkyl group is more preferable.

As the alkyl group represented by R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ , an alkyl group having 1 to 12 carbon atoms is preferable, and an alkyl group having 1 to 10 carbon atoms is more preferable. Desirably, an alkyl group having 3 to 8 carbon atoms is more desirable, and an alkyl group having 4 to 6 carbon atoms is more desirable.
The alkyl group may be linear, branched, or cyclic.
Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, and a neopentyl group. Tert-pentyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, n-heptyl group, isoheptyl group, sec-heptyl group, tert-heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, n-nonyl group, isononyl group, sec-nonyl group, tert-nonyl group, n-decyl group, isodecyl group, sec-decyl group, tert-decyl group, n-undecyl group , Isoundecyl group, n-dodecyl group, and isododecyl group.
Among these, from the viewpoint of suppressing the decomposition of a specific squarylium-croconium compound, a branched alkyl group is preferable, and an alkyl group having a structure with three or more terminals (tertiary (tert) alkyl group) is more preferable. Specifically, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isoheptyl, sec- Heptyl group, tert-heptyl group, isooctyl group, sec-octyl group, tert-octyl group, isononyl group, sec-nonyl group, tert-nonyl group, isodecyl group, sec-decyl group, tert-decyl group, isoundecyl group, Alternatively, an isododecyl group is preferable, and a tert-butyl group, a tert-pentyl group, a tert-hexyl group, a tert-heptyl group, a tert-octyl group, a tert-nonyl group, and a tert-decyl group are more preferable. Among them, a tert-butyl group is particularly preferred.

  Note that the alkyl group may be substituted with a halogen atom (for example, fluorine or chlorine).

Specific examples and preferred ranges of the alkyl group in the alkoxy group represented by R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ are as follows: R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and It is the same as the alkyl group represented by R ^{31 to} R ³⁴ .

The aryl group represented by R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ is preferably a group obtained by removing one hydrogen atom from a benzene ring of benzene or alkylbenzene, and has the following structural formula Is more preferable.

In the above structural formula, * represents a bonding site to the central skeleton, and R ¹⁰ represents hydrogen or an alkyl group. As the alkyl group represented by R ¹⁰ , an alkyl group having 2 to 8 carbon atoms is desirable.
For an alkyl group represented by R ^10, and specific examples and preferred ranges ^are the same as the alkyl group represented by ^{R 11} to ^{R 14, R 21} through ^{R 24,} and ^{R 31} to ^{R 34.}

  The aryl group may be substituted with a halogen atom (for example, fluorine, chlorine).

About the alkyl group in the aralkyl group represented by R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ , specific examples and preferred ranges thereof are R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and It is the same as the alkyl group represented by R ^{31 to} R ³⁴ . Further, specific examples and preferred ranges of the aryl group in the aralkyl group are the same as those of the aryl group represented by R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ³⁴ .

· ^{R 15} to ^{R 16, R 25} to ^{R 26,} and ^{R 35} to ^{R 36}
In the general formulas (I-1), (I-2) and (I-3), R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , and R ^{35 to} R ³⁶ each independently represent hydrogen. Or an alkyl group.

The alkyl group represented by R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , and R ^{35 to} R ³⁶ may be linear, branched, or cyclic. When it is linear or branched, it preferably has 1 to 6 carbon atoms (more preferably 1 to 3 carbon atoms, and still more preferably 1 carbon atoms). When it is cyclic (cycloalkyl group), it preferably has 3 or more and 6 or less (more preferably 3 or more and 4 or less, more preferably 3).
Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert- Examples include a pentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , and R ^{35 to} R ³⁶ are preferably hydrogen or a methyl group, and more preferably hydrogen.

・ X and Y
In the general formulas (I-1), (I-2) and (I-3), X represents oxygen, sulfur, selenium, or tellurium, and a plurality of Xs represent the same element. Y represents oxygen, sulfur, selenium, or tellurium, represents an element different from X, and a plurality of Y represent the same element.

X is preferably one of oxygen and sulfur, and Y is preferably oxygen or sulfur which is different from X.
In other words, the resin composition according to the present embodiment preferably contains at least two of the following compounds [ii1], [ii2], and [ii3].
[ii1] at least one selected from the group consisting of compounds represented by general formula (II-1)
[ii2] at least one selected from the group consisting of compounds represented by general formula (II-2)
[ii3] at least one selected from the group consisting of compounds represented by formula (II-3)

(In the general formula (II-1), the general formula (II-2) and the general formula (II-3), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , R ³⁴ , R ¹⁵ , R ¹⁶ , R ²⁵ , R ²⁶ , R ³⁵ , R ³⁶ , A ¹ , A ² , and A ³ are represented by the general formula (I-1), It has the same meaning as each group in formula (I-2) and general formula (I-3).)

· ^A 1, ^{A 2,} and ^{A 3}
In the general formulas (I-1), (I-2) and (I-3), A ¹ , A ² and A ³ are each independently represented by the general formula (a1). A divalent group (that is, a squarylium-based compound) or a divalent group represented by the general formula (a2) (that is, a croconium-based compound).
A ¹ , A ² , and A ³ are preferably a divalent group represented by the general formula (a1), that is, in this embodiment, more preferably contain a squarium-based compound.

-Specific examples Here, specific examples of specific squarylium-croconium compounds are shown.
Specific examples of the compound represented by the formula (I-1) include, for example, the following compounds.
As specific examples of the compound represented by the general formula (I-3), the following compounds also listed as specific examples of the compound represented by the general formula (I-1) (where X is Y, A ¹ to ^{A 3,} are each ^{R 11} or ^{R 16 R 31} to ^{R 36,} replaced) it can be mentioned.

In the compounds represented by the general formula (I-1) listed above, X is preferably any one of oxygen and sulfur.
A ¹ is preferably a divalent group represented by the general formula (a1).
Among the above specific examples, compound I-1- (11) is preferable.

  In addition, specific examples of the compound represented by the general formula (I-2) include the following compounds.

In the compounds represented by the general formula (I-2) listed above, X is preferably any one of oxygen and sulfur, and Y is preferably oxygen or sulfur which is different from X. preferable.
A ² is preferably a divalent group represented by the general formula (a1).
Among the above specific examples, compound I-2- (11) is preferable.

-Combination in a mixture The resin composition according to the present embodiment includes, as specific squarylium-croconium-based compounds, (2) at least one selected from the group consisting of compounds represented by general formula (I-1); A) a mixture of a compound represented by the general formula (I-2) and at least one selected from the group consisting of compounds represented by the general formula (I-3).

The following combinations may be mentioned as combinations in a specific squarylium-croconium compound mixture.
a) One or more (preferably one) of the compounds represented by the general formula (I-1) and one or more (preferably one) of the compounds represented by the general formula (I-2) B) one or more (preferably one) of the compounds represented by the general formula (I-1) and one or more (preferably one) the compounds represented by the general formula (I-3) C) one or more (preferably one) compound represented by the general formula (I-1) and one or more compound represented by the general formula (I-2) (Preferably one) and one or more (preferably one) compounds represented by formula (I-3) in combination

  From the viewpoint of ease of production, the combination of the above a) or c) is more preferable.

In the case of the mixture of the above a), from the viewpoint of ease of production, the compound represented by the general formula (I-1) and the compound represented by the general formula (I-2) may each contain one kind. preferable.
When each compound is contained one by one, R ¹¹ and R ²¹ and R ¹² and R ^{12 in} the general formulas (I-1) and (I-2) from the viewpoint of ease of production and dispersibility in the resin composition. ²² , R ¹³ and R ²³ , R ¹⁴ and R ²⁴ , R ¹⁵ and R ²⁵ , R ¹⁶ and R ²⁶ , and A ¹ and A ² are all the same (that is, the structures other than X and Y are the same) Is preferable.

In the case of the mixture of b), from the viewpoint of ease of production, it is more preferable that the compound represented by the general formula (I-1) and the compound represented by the general formula (I-3) are each contained one by one. preferable.
When each compound is contained one by one, R ¹¹ and R ³¹ , R ¹² and R in the general formulas (I-1) and (I-3) are considered from the viewpoints of ease of production and dispersibility in the resin composition. ^{32, R 13} and ^{R 33, R 14} and ^{R 34, R 15} and ^{R 35, R 16} and ^{R 36,} is and ^{a 1} and ^{a 3,} it (i.e. structures other than X and Y are the same both the same Is preferable.

In the case of the mixture of the above c), from the viewpoint of ease of production, the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) More preferably, each of the compounds represented by the formula is contained one by one.
Further, when each compound is contained one by one, R ¹¹ and R ¹¹ in the general formulas (I-1), (I-2) and (I-3) are considered from the viewpoint of ease of production and dispersibility in the resin composition. ²¹ and R ³¹ , R ¹² and R ²² and R ³² , R ¹³ and R ²³ and R ³³ , R ¹⁴ and R ²⁴ and R ³⁴ , R ¹⁵ and R ²⁵ and R ³⁵ , R ¹⁶ and R ²⁶ and R ³⁶ , and a ¹ and a ² and a ³ are, it both the same (that structures other than that is X and Y are the same) are preferred.

Above all, the mixture of the specific squarylium-croconium compound is preferably the following combination.
・ Mixture 1
A compound represented by the general formula (I-1), wherein X = S, A ¹ = general formula (a1), R ^{11 to} R ¹⁴ = tert-butyl group, and R ^{15 to} R ¹⁶ = hydrogen;
A compound represented by the general formula (I-2), wherein X = S, Y = O, A ² = general formula (a1), R ^{21 to} R ²⁴ = tert-butyl group, and R ^{25 to} R ²⁶ = hydrogen・ Mixture ・ Mixture 2
A compound represented by the general formula (I-1), wherein X = S, A ¹ = general formula (a1), R ^{11 to} R ¹⁴ = tert-butyl group, and R ^{15 to} R ¹⁶ = hydrogen;
A compound represented by the general formula (I-2), wherein X = S, Y = O, A ² = general formula (a1), R ^{21 to} R ²⁴ = tert-butyl group, and R ^{25 to} R ²⁶ = hydrogen ,
A mixture of a compound represented by the general formula (I-3), wherein Y = O, A ³ = general formula (a1), R ^{31 to} R ³⁴ = tert-butyl group, and R ^{35 to} R ³⁶ = hydrogen Mixture 3
A compound represented by the general formula (I-1), wherein X ＝ O, A ¹ = general formula (a1), R ^{11 to} R ¹⁴ = tert-butyl group, and R ^{15 to} R ¹⁶ = hydrogen;
A compound represented by the general formula (I-2), wherein X = O, Y = S, A ² = general formula (a1), R ^{21 to} R ²⁴ = tert-butyl group, and R ^{25 to} R ²⁶ = hydrogen ,
A mixture of a compound represented by the general formula (I-3), wherein Y = S, A ³ = general formula (a1), R ^{31 to} R ³⁴ = tert-butyl group, and R ^{35 to} R ³⁶ = hydrogen Mixture 4
A compound represented by the general formula (I-1), wherein X ＝ O, A ¹ = general formula (a1), R ^{11 to} R ¹⁴ = tert-butyl group, and R ^{15 to} R ¹⁶ = hydrogen;
A compound represented by the general formula (I-2), wherein X = O, Y = S, A ² = general formula (a1), R ^{21 to} R ²⁴ = tert-butyl group, and R ^{25 to} R ²⁶ = hydrogen , A mixture of

-Composition ratio in mixture In the present embodiment, in the specific squarylium-croconium-based compound mixture, the compound represented by the general formula (I-1) or the compound represented by the general formula (I-2) is used as a main component. It is preferable that the compound represented by the general formula (I-1) be contained as a main component.
In the specific squarylium-croconium compound mixture, the proportion of the main component is preferably more than 50% by mass, that is, the balance (the compound represented by the general formula (I-1)) And the content of the compound represented by the general formula (I-2) which is not the main component, the compound represented by the general formula (I-3), or both) is less than 50% by mass. preferable.

In addition, the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) each include one kind or two kinds. The above may be used in combination, and the concept of the main component and the remainder when two or more kinds are included is a total amount of two or more kinds.
Further, the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) may each contain one kind at a time. More preferred.

The proportion of the main component in the specific squarylium-croconium-based compound mixture is from 85.0% by mass to 99.9% by mass (the remainder is from 0.1% by mass to 15.0% by mass). More preferably, it is 90 mass% or more and 99 mass% or less (the balance is 1 mass% or more and 10 mass% or less), and 92 mass% or more and 98 mass% or less (the balance is 2 mass% or more and 8 mass% or less). Is more preferable.
When the proportion of the main component is 85.0% by mass or more (the remainder is 15.0% by mass or less), characteristics such as infrared absorption performance can be easily controlled to a required range. On the other hand, when the proportion of the main component is 99.9% by mass or less (the balance being 0.1% by mass or more), color turbidity is suppressed and infrared absorption performance is enhanced.

The composition ratio of each compound contained in the specific squarylium-croconium compound mixture is measured by the following high-performance liquid chromatography (HPLC).
-Measurement by HPLC-
A high performance liquid chromatography device (HPLC device, manufacturer: Shimadzu Corporation, model number: LC-10A) is used. As an HPLC column, a column manufactured by Chemco, Inc., trade name: CHEMCOSORB, product number: 5-ODS-H, inner diameter: 4.6 mm, and length: 150 mm is used. The measurement conditions were as follows: column temperature: 45 ° C., injection amount of the measurement sample: 10 μl, flow rate of the measurement sample: 1 ml / min, detection wavelength: 254 nm, mobile phase: a mixed solution of acetonitrile and water (acetonitrile: water = 9: The condition of 1) is assumed.

-Method for synthesizing a mixture Here, a method for synthesizing a mixture of specific squarylium-croconium compounds will be described.
First, a method for synthesizing a mixture of a compound represented by the general formula (I-1), a compound represented by the general formula (I-2) and a compound represented by the general formula (I-3), The mixture of the compound represented by the formula (I-1) and the compound represented by the formula (I-2) can be synthesized, for example, by the following method.

-Synthesis method 1
A mixture of the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) is, for example, described in the following (Scheme 1 ), (Scheme 2-1), (Scheme 2-2), and (Scheme 3). However, in the following scheme, A ¹ , A ² , and A ³ in the general formulas (I-1), (I-2), and (I-3) are the general formulas (a1), and R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , R ^{31 to} R ³⁴ are the same group (R _a ), R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , R ^{35 to} R ³⁶ are hydrogen, X is sulfur, and Y is Is an example in which is oxygen.

<Scheme 1>
First, under an inert atmosphere and cooled, the starting material 1 is allowed to act dropwise on a solution of an organic magnesium halide (eg, Grignard reagent, eg, ethyl magnesium chloride) in an organic solvent (eg, tetrahydrofuran). Thereafter, the temperature may be returned to room temperature (eg, 23 ° C. to 25 ° C.) or higher in order to complete the reaction. Then, under cooling, a formic acid derivative (eg, ethyl formate) is allowed to act dropwise. Thereafter, the temperature may be returned to room temperature (eg, 23 ° C. to 25 ° C.) or higher in order to complete the reaction. The organic matter is extracted from the mixture after the reaction, and Intermediate A is obtained from the separated organic layer.

  Next, the intermediate A and an oxidizing reagent (eg, manganese oxide) are added to a solvent (eg, cyclohexane), and the mixture is heated and refluxed to cause a reaction. Water generated during the reaction may be removed. Intermediate B is obtained from the organic layer of the reaction mixture. In addition, you may refine when obtaining the intermediate B.

<Scheme 2-1>
Next, the intermediate B is subjected to a cycloaddition reaction. For example, an intermediate in which sulfur is present at a position corresponding to X in the general formulas (I-1) and (I-2) is obtained by using sodium hydrogen monosulfide n-hydrate.
For example, sodium hydrogen sulfide n-hydrate is added to a solvent (for example, ethanol or the like), and the intermediate B is added dropwise under cooling. Thereafter, the reaction is carried out at room temperature (for example, 23 ° C. to 25 ° C.). After the solvent is removed from the reaction solution, salt is added until the solution is saturated, and the mixture is separated to collect the organic phase, thereby obtaining an intermediate C1 from the organic phase. In addition, purification may be performed when obtaining the intermediate C1.
Then, under an inert atmosphere, a solvent (for example, anhydrous tetrahydrofuran or the like) and the intermediate C1 are mixed, and a Grignard reagent (for example, methylmagnesium bromide) is added dropwise. After completion of the dropwise addition, the reaction solution is heated to reflux, and then, under cooling, ammonium bromide is added dropwise. The separated organic layer is dried and concentrated to obtain the intermediate D1.

<Scheme 2-2>
In addition, a cycloaddition reaction is performed on the intermediate B in a step different from the scheme 2-1. For example, an intermediate in which oxygen is present at a position corresponding to Y in the general formulas (I-2) and (I-3) is obtained using p-toluenesulfonic acid.
For example, the intermediate B is dissolved in a solvent (such as methanol), p-toluenesulfonic acid is added, and the mixture is heated to reflux. After removing the solvent from the reaction solution, dilution, washing and concentration are performed under reduced pressure, and the residue is distilled under reduced pressure to obtain an intermediate C2. In addition, purification may be performed when obtaining the intermediate C2.
Then, under an inert atmosphere, a solvent (for example, anhydrous tetrahydrofuran or the like) and the intermediate C2 are mixed, and a Grignard reagent (for example, methylmagnesium bromide) is added dropwise. After completion of the dropwise addition, the reaction solution is heated to reflux, and then, under cooling, ammonium bromide is added dropwise. The separated organic layer is dried and concentrated to obtain the intermediate D2.

<Scheme 3>
Then, under an inert atmosphere, the intermediate D1, the intermediate D2, and the squaric acid are dispersed in a solvent (for example, a mixed solvent of cyclohexane and isobutanol), and a basic compound (for example, pyridine or the like) is added, followed by heating under reflux. And a mixture of compound (I-1) -a, compound (I-2) -a and compound (I-3) -a. Water generated during the reaction may be removed. Further, purification, isolation, concentration and the like may be performed.

  Note that the ratio of the compound (I-1) -a, the compound (I-2) -a, and the compound (I-3) -a is determined by the mixing ratio of the intermediate D1 and the intermediate D2 in the scheme 3. It is controlled by adjusting.

  In addition, in order to obtain a mixture of the compound (I-1) -a and the compound (I-2) -a, in the scheme 3, the mixing ratio of the intermediate D1 among the intermediate D1 and the intermediate D2 is increased ( (For example, 85% by mass or more), and after heating and refluxing to obtain a mixture, purification is performed. Thereby, compound (I-3) -a is reduced to below the detection limit, and a mixture of compound (I-1) -a and compound (I-2) -a is obtained.

-Synthesis method-2-
Next, a group in which some or all of R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , and R ^{31 to} R ^{34 in} the general formulas (I-1), (I-2), and (I-3) are different. The synthesis route of the compound is described. For example, in the above-mentioned <Scheme 1>, it can be synthesized by changing the synthesis of Intermediate A to the following <Scheme 1 ′>.

In the above scheme 1 ′, first, the starting substance 2 and the additional substance 2 are added to an organic solution (for example, a tetrahydrofuran solution or the like) to which a Grignard reagent (for example, ethylmagnesium bromide) has been added and reacted. A strong acid (eg, hydrochloric acid, etc.) is added to the solution after the reaction under cooling, and then ether is added at room temperature (eg, 23 ° C. to 25 ° C.) to obtain an intermediate A ′ from the organic layer. In addition, purification may be performed when obtaining the intermediate A ′.
Then, in the above-mentioned <Scheme 1>, <Scheme 2-1>, <Scheme 2-2> and <Scheme 3>, by changing the intermediate A to the intermediate A ′, the general formula (I-1) In (I-2) and (I-3), R ¹¹ , R ¹³ , R ²¹ , R ²³ , R ³¹ , and R ³³ are “R ₁ ”, R ¹² , R ¹⁴ , R ²² , R ²⁴ , and R ^32. , And R ³⁴ are “R ₂ ”.

-Synthesis method-No.3-
Further, R ¹¹ , R ¹² , R ²¹ , R ²² , R ³¹ and R ³² in the general formulas (I-1), (I-2) and (I-3) are the same group “R _b ”, The synthesis of a mixture in which R ¹³ , R ¹⁴ , R ²³ , R ²⁴ , R ³³ , and R ³⁴ are “R _c ” will be described. In the above <Scheme 1>, an intermediate B ′ is synthesized using a starting material 1 ′ in which R _a in the starting material 1 is replaced with R _b , and in a separate step, R _a in the starting material 1 is changed to R _c Intermediate B ″ is synthesized using the starting material 1 ″ in place of the above, and the above mixture can be synthesized using the intermediate B ′ and the intermediate B ″.

-Synthesis Method 4-
Further, according to a scheme different from the above-mentioned synthesis method-No. 1, the compound represented by the general formula (I-1), the compound represented by the general formula (I-2) and the compound represented by the general formula (I-3) A mixture of the compound represented by the general formula (I-1) and a mixture of the compound represented by the general formula (I-2) is obtained.
For example, it can be synthesized according to the following (Scheme I), (Scheme II), and (Scheme III). However, in the following scheme, A ¹ , A ² , and A ³ in the general formulas (I-1), (I-2), and (I-3) are the general formulas (a1), and R ^{11 to} R ¹⁴ , R ^{21 to} R ²⁴ , R ^{31 to} R ³⁴ are the same group (R _a ), R ^{15 to} R ¹⁶ , R ^{25 to} R ²⁶ , R ^{35 to} R ³⁶ are hydrogen, X is sulfur, and Y is Is an example in which is oxygen.

<Scheme I>
The starting material 3 is added to an organic solvent (for example, toluene or the like) to which sodium amide is added, and a toluene solution of acetaldehyde is added dropwise while heating and stirring. After stirring, the mixture is cooled, acidified by adding an acidic substance (for example, aqueous hydrochloric acid), and the organic layer is separated to obtain an intermediate b. When obtaining the intermediate b, concentration under reduced pressure or distillation under reduced pressure may be performed.

<Scheme II>
Next, the intermediate b is subjected to a cycloaddition reaction. For example, using acetic anhydride ((CH ₃ CO) ₂ O) and hydrogen sulfide (H ₂ S), a position corresponding to X in the general formulas (I-1), (I-2) and (I-3). And an intermediate in which oxygen is present at a position corresponding to Y.
For example, acetic anhydride is added to the intermediate b and the mixture is cooled, and perchloric acid is added dropwise while introducing hydrogen sulfide, followed by stirring. After stirring, the precipitated solid is filtered to obtain Intermediate d1 and Intermediate d2.

<Scheme III>
Next, the intermediate d1, the intermediate d2, and squaric acid are dispersed in a solvent (eg, a mixed solvent of toluene and isobutanol), a basic compound (eg, pyridine or the like) is added, and the mixture is heated under reflux to give the compound (I- A mixture of 1) -a, compound (I-2) -a and compound (I-3) -a is obtained. Water generated during the reaction may be removed. Further, purification, isolation, concentration and the like may be performed.

In addition, the ratio of the compound (I-1) -a, the compound (I-2) -a, and the compound (I-3) -a is determined by the amount of hydrogen sulfide (H ₂ S) introduced in the scheme II. It is controlled by adjusting.

  In order to obtain a mixture of the compound (I-1) -a and the compound (I-2) -a, the ratio of the intermediate d1 is increased among the intermediates d1 and d2 obtained in the scheme II. (For example, 85% by mass or more), and purified by heating and refluxing to obtain a mixture. Thereby, compound (I-3) -a is reduced to below the detection limit, and a mixture of compound (I-1) -a and compound (I-2) -a is obtained.

-Other synthesis methods-
Further, a compound represented by the general formula (I-1), a compound represented by the general formula (I-2), and a compound represented by the general formula (I-3) are separately synthesized, and after the synthesis, By mixing, a specific squarylium-croconium-based compound mixture in the present embodiment may be obtained.
In addition, according to this method, the compound represented by the general formula (I-2) including the compound represented by the general formula (I-1) and the compound represented by the general formula (I-3) is used. Mixtures that do not include can also be prepared.

-Physical properties of mixture The maximum absorption wavelength of a specific squarylium-croconium-based compound mixture in a tetrahydrofuran (THF) solution is preferably in the range of 760 nm to 1200 nm, more preferably 780 nm to 1100 nm, and preferably 800 nm. The range of not less than 1000 nm is more preferable.

The molar extinction coefficient at the maximum absorption wavelength in a tetrahydrofuran (THF) solution of a specific squarylium-croconium-based compound mixture is preferably from 100,000 Lmol ^-1 cm ^{-1 to} 600,000 Lmol ^-1 cm ^-1 , and preferably 200,000 Lmol. preferably ^-1 cm ^-1 or more 600,000 ^{L mol} -1 ^{cm -1} or less, more preferably 250,000 ^{L mol} -1 ^{cm -1} or more 600,000 ^{L mol} -1 ^{cm -1} or less.

The compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) are all solid-dispersed in the resin composition. It is better to be in a state. When present in the resin composition in a solid dispersion state, the mass average particle diameter is preferably from 10 nm to 1000 nm, more preferably from 10 nm to 500 nm, and even more preferably from 20 nm to 300 nm.
In addition, the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3) are dispersed in a molecular level. It may be present in the resin composition in a state.

-Other infrared absorbers In addition to the specific squarylium-croconium-based compound mixture, the resin composition according to the present embodiment may further contain a known infrared absorber. For example, when the resin composition is used for a toner for developing an electrostatic image, a known infrared absorbing agent may be used in combination as long as the fixing property is not affected.
Known infrared absorbers include, for example, cyanine compounds, merocyanine compounds, benzenethiol-based metal complexes, mercaptophenol-based metal complexes, aromatic diamine-based metal complexes, diimonium compounds, aminium compounds, nickel complex compounds, phthalocyanine-based compounds, anthraquinones Compounds, naphthalocyanine compounds and the like can be used.
Specific known infrared absorbers include nickel metal complex-based infrared absorbers (SIR-130, SIR-132, manufactured by Mitsui Chemicals, Inc.), bis (dithiobenzyl) nickel (MIR-101, manufactured by Midori Kagaku), Bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel (manufactured by Midori Kagaku: MIR-102), tetra-n-butylammonium bis (cis-1,2-diphenyl-) 1,2-ethylenedithiolate) nickel (manufactured by Midori Kagaku: MIR-1011), tetra-n-butylammonium bis [1,2-bis (p-methoxyphenyl) -1,2-ethylenedithiolate] nickel ( Midori Chemical Co., Ltd .: MIR-1021), bis (4-tert-1,2-butyl-1,2-dithiophenolate) nickel-tet -N-butylammonium (manufactured by Sumitomo Seika Co., Ltd .: BBDT-NI), cyanine-based infrared absorber (manufactured by Fujifilm (registered trademark): IRF-106, IRF-107), cyanine-based infrared absorber (Yamamoto Kasei Co., Ltd.) , YKR2900), aminium, diimmonium-based infrared absorber (NIR-AM1, IM1 manufactured by Nagase Chemtech), immonium compound (CIR-1080, CIR-1081 manufactured by Nippon Carlit), aminium compound (manufactured by Nippon Carlit: CIR-960, CIR-961), anthraquinone compounds (IR-750, manufactured by Nippon Kayaku), aminium compounds (IRG-002, IRG-003, IRG-003K, manufactured by Nippon Kayaku), polymethine compounds (Manufactured by Nippon Kayaku Co., Ltd .: IR-820B), diimonium-based compound (manufactured by Nippon Kayaku Co., Ltd .: IR G-022, IRG-023), dianine compound (CY-2, CY-4, CY-9, manufactured by Nippon Kayaku), soluble phthalocyanine (TX-305A, manufactured by Nippon Shokubai), naphthalocyanine (Yamamoto Kasei Co., Ltd.) Manufactured by YKR5010, manufactured by Sanyo Dyestuffs Co., Ltd .: sample 1), inorganic materials (Shin-Etsu Chemical Co., Ltd .: ytterbium UU-HP, manufactured by Sumitomo Metal Co., Ltd .: injumtin oxide), and the like.
Of these, diimonium compounds are preferred.

〔resin〕
The resin composition according to the present embodiment further includes a resin (binder resin).

-Binder resin-
Examples of the binder resin include styrenes (eg, styrene, parachlorostyrene, α-methylstyrene, etc.) and (meth) acrylates (eg, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid) n-butyl, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc., ethylenically unsaturated nitriles (for example, acrylonitrile, Methacrylonitrile, etc.), vinyl ethers (eg, vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropenyl ketone, etc.), olefins (eg, ethylene, propylene Emissions, a homopolymer of a monomer such as butadiene) and the like, or a vinyl-based resin composed of these monomers with two or more combinations copolymer.
As the binder resin, for example, an epoxy resin, a polyester resin, a polyurethane resin, a polyamide resin, a cellulose resin, a polyether resin, a non-vinyl-based resin such as modified rosin, a mixture of these and the vinyl-based resin, or a mixture thereof. A graft polymer obtained by polymerizing a vinyl monomer in the coexistence is also included.
One of these binder resins may be used alone, or two or more thereof may be used in combination.

As the binder resin, a polyester resin is preferable.
Examples of the polyester resin include known polyester resins.

  Examples of the polyester resin include a condensation polymer of a polyvalent carboxylic acid and a polyhydric alcohol. As the polyester resin, a commercially available product may be used, or a synthetic resin may be used.

Examples of the polycarboxylic acid include aliphatic dicarboxylic acids (eg, oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.) Alicyclic dicarboxylic acid (eg, cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acid (eg, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), anhydrides thereof, or lower (eg, having 1 or more carbon atoms) 5 or less) alkyl esters. Among these, as the polyvalent carboxylic acid, for example, an aromatic dicarboxylic acid is preferable.
The polyvalent carboxylic acid may be used in combination with a dicarboxylic acid and a trivalent or higher carboxylic acid having a crosslinked structure or a branched structure. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, anhydrides thereof, and lower (for example, having 1 to 5 carbon atoms) alkyl esters thereof.
Polycarboxylic acids may be used alone or in combination of two or more.

Examples of the polyhydric alcohol include aliphatic diols (eg, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.) and alicyclic diols (eg, cyclohexanediol, cyclohexanedimethanol, Hydrogenated bisphenol A, etc.) and aromatic diols (eg, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide adduct, etc.). Among these, as the polyhydric alcohol, for example, an aromatic diol and an alicyclic diol are preferable, and an aromatic diol is more preferable.
As the polyhydric alcohol, a tri- or higher polyhydric alcohol having a crosslinked structure or a branched structure may be used together with the diol. Examples of the trihydric or higher polyhydric alcohol include glycerin, trimethylolpropane, and pentaerythritol.
Polyhydric alcohols may be used alone or in combination of two or more.

The glass transition temperature (Tg) of the polyester resin is preferably from 50 ° C to 80 ° C, more preferably from 50 ° C to 65 ° C.
The glass transition temperature is determined from a DSC curve obtained by differential scanning calorimetry (DSC), and is more specifically described in JIS K 7121-1987 “Method for measuring the transition temperature of plastic”. Of "extrapolated glass transition onset temperature".

The weight average molecular weight (Mw) of the polyester resin is preferably from 5,000 to 1,000,000, and more preferably from 7000 to 500,000.
The number average molecular weight (Mn) of the polyester resin is preferably from 2,000 to 100,000.
The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or more and 100 or less, more preferably 2 or more and 60 or less.
The weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). The molecular weight measurement by GPC is performed using a Tosoh column and TSKgel Super HM-M (15 cm) using a Tosoh GPC / HLC-8120GPC as a measuring device, using a THF solvent. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample.

The polyester resin can be obtained by a well-known manufacturing method. Specifically, for example, it can be obtained by a method in which the polymerization temperature is set to 180 ° C. or higher and 230 ° C. or lower, the pressure in the reaction system is reduced as necessary, and the reaction is carried out while removing water and alcohol generated during condensation.
When the raw material monomers are not dissolved or compatible at the reaction temperature, a high boiling point solvent may be added as a solubilizing agent to dissolve the monomers. In this case, the polycondensation reaction is performed while distilling off the dissolution aid. When a monomer having poor compatibility exists in the copolymerization reaction, the monomer having poor compatibility and the monomer or acid or alcohol to be polycondensed are condensed in advance, and then polymerized together with the main component. It is good to condense.

<Electrostatic image developing toner>
Next, the electrostatic image developing toner according to the exemplary embodiment will be described.
The electrostatic image developing toner according to the present embodiment (hereinafter, also simply referred to as “toner”) includes the resin composition according to the present embodiment described above. The toner according to the present embodiment includes toner particles and, if necessary, an external additive. The above-described resin composition according to the present embodiment is preferably contained in the toner particles.

  In the toner particles, a mixture of the above-mentioned specific squarylium-croconium-based compound (that is, at least one selected from the group consisting of compounds represented by the general formula (I-1) and the compound represented by the general formula (I-2)) Of at least one compound selected from the group consisting of the compound represented by formula (I-3) and the compound represented by formula (I-3) is 0.01% by mass to 5% by mass with respect to the total mass of the toner particles. The content is desirably not more than 0.01% by mass, more desirably from 0.01% by mass to 1% by mass, and more desirably from 0.01% by mass to 0.5% by mass.

  The content of the binder resin in the toner particles is, for example, preferably from 40% by weight to 95% by weight, more preferably from 50% by weight to 90% by weight, and more preferably from 60% by weight to 90% by weight based on the whole toner particles. It is more preferably at most 85% by mass.

(Toner particles)
The toner particles may include, for example, a colorant, a release agent, and other additives in addition to the resin composition according to the exemplary embodiment.

-Coloring agent-
Examples of the coloring agent include carbon black, chrome yellow, Hansa yellow, benzidine yellow, slen yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, brilliant carmine 3B, and brilliant. Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Pigment Red, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Various pigments such as malachite green oxalate, or acridine, xanthene, Dyes such as benzoquinone, azine, anthraquinone, thioindico, dioxazine, thiazine, azomethine, indico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, and thiazole And the like.
One type of colorant may be used alone, or two or more types may be used in combination.

  The colorant may be a surface-treated colorant as necessary, or may be used in combination with a dispersant. In addition, a plurality of colorants may be used in combination.

  The content of the colorant is, for example, preferably from 1% by mass to 30% by mass, and more preferably from 3% by mass to 15% by mass, based on the whole toner particles.

-Release agent-
Examples of the release agent include hydrocarbon wax; natural wax such as carnauba wax, rice wax and candelilla wax; synthetic or mineral / petroleum wax such as montan wax; ester wax such as fatty acid ester and montanic acid ester. And the like. The release agent is not limited to this.

The melting temperature of the release agent is preferably from 50 ° C to 110 ° C, more preferably from 60 ° C to 100 ° C.
The melting temperature is determined from the DSC curve obtained by differential scanning calorimetry (DSC) according to the “melting peak temperature” described in JIS K 7121-1987 “Method for measuring the transition temperature of plastics”. .

  The content of the release agent is, for example, preferably from 1% by mass to 20% by mass, more preferably from 5% by mass to 15% by mass, based on the whole toner particles.

-Other additives-
Examples of the other additives include well-known additives such as a magnetic substance, a charge control agent, and an inorganic powder. These additives are contained in the toner particles as internal additives.

-Characteristics of toner particles-
The toner particles may be toner particles having a single-layer structure or toner particles having a so-called core-shell structure composed of a core (core particle) and a coating layer (shell layer) covering the core. You may.
Here, the toner particles having a core-shell structure are configured to include, for example, a mixture of a binder resin and a specific squarylium-croconium-based compound and, if necessary, other additives such as a colorant and a release agent. It is preferable that the core portion and the coating layer containing a binder resin are included.

  The volume average particle diameter (D50v) of the toner particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less.

Various average particle diameters and various particle size distribution indexes of the toner particles were measured using Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolytic solution was measured using ISOTON-II (manufactured by Beckman Coulter). You.
In the measurement, 0.5 mg or more and 50 mg or less of a measurement sample are added to 2 ml of a 5% aqueous solution of a surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is added to 100 ml or more and 150 ml or less of the electrolytic solution.
The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for 1 minute by an ultrasonic disperser, and the particle size distribution of particles having a particle size in a range of 2 μm to 60 μm is measured by a Coulter Multisizer II using an aperture having an aperture diameter of 100 μm. Measure. The number of particles to be sampled is 50,000.
A volume distribution and a number are plotted from the smaller diameter side for the particle size range (channel) divided based on the measured particle size distribution, and the particle size at which the accumulation becomes 16% is determined as the volume particle size D16v and the number particle size. D16p, the particle diameter at which the accumulation is 50% is defined as a volume average particle diameter D50v, the accumulation number average particle diameter D50p, and the particle diameter at which the accumulation is 84% are defined as volume particle diameter D84v and number particle diameter D84p.
Using these, the volume particle size distribution index (GSDv) is calculated as (D84v / D16v) ^1/2 , and the number particle size distribution index (GSDp) is calculated as (D84p / D16p) ^1/2 .

  The shape factor SF1 of the toner particles is preferably from 110 to 150, more preferably from 120 to 140.

The shape factor SF1 is obtained by the following equation.
Formula: SF1 = (ML ² / A) × (π / 4) × 100
In the above formula, ML indicates the absolute maximum length of the toner, and A indicates the projected area of the toner.
Specifically, the shape factor SF1 is quantified by mainly analyzing a microscope image or a scanning electron microscope (SEM) image using an image analyzer, and is calculated as follows. That is, the optical microscope image of the particles scattered on the slide glass surface is taken into a Luzex image analyzer by a video camera, the maximum length and the projected area of 100 particles are obtained, calculated by the above formula, and the average value thereof is obtained. can get.

(External additives)
Examples of the external additive include inorganic particles. As the inorganic particles, SiO ₂ , TiO ₂ , Al ₂ O ₃ , CuO, ZnO, SnO ₂ , CeO ₂ , Fe ₂ O ₃ , MgO, BaO, CaO, K ₂ O, Na ₂ O, ZrO ₂ , CaO. SiO ₂ , K ₂ O. (TiO ₂ ) n, Al ₂ O ₃ .2SiO ₂ , CaCO ₃ , MgCO ₃ , BaSO ₄ , MgSO _{4 and the} like.

The surface of the inorganic particles as an external additive is preferably subjected to a hydrophobic treatment. The hydrophobic treatment is performed, for example, by immersing the inorganic particles in a hydrophobic treatment agent. The hydrophobizing agent is not particularly limited, and examples thereof include a silane coupling agent, a silicone oil, a titanate coupling agent, and an aluminum coupling agent. These may be used alone or in combination of two or more.
The amount of the hydrophobizing agent is usually, for example, 1 part by mass or more and 10 parts by mass or less based on 100 parts by mass of the inorganic particles.

  Examples of the external additive include resin particles (resin particles such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin), a cleaning activator (for example, a metal salt of a higher fatty acid represented by zinc stearate, a fluoropolymer, Particles).

  The external additive amount of the external additive is, for example, preferably from 0.01% by mass to 5% by mass, more preferably from 0.01% by mass to 2.0% by mass, based on the toner particles.

(Method of manufacturing toner)
Next, a method for manufacturing the toner according to the exemplary embodiment will be described.
The toner according to the exemplary embodiment is obtained by externally adding an external additive to the toner particles after manufacturing the toner particles.

The toner particles may be produced by any of a dry production method (for example, a kneading and pulverizing method) and a wet production method (for example, an aggregation and coalescence method, a suspension polymerization method, and a dissolution suspension method). The production method of the toner particles is not particularly limited, and a known production method is employed.
Among these, it is preferable to obtain the toner particles by the aggregation and coalescence method.

Specifically, for example, when the toner particles are manufactured by an aggregation coalescence method,
A step of preparing a resin particle dispersion in which resin particles serving as a binder resin are dispersed (resin particle dispersion preparation step); and a step of mixing a resin particle dispersion in another resin particle dispersion (if necessary, (In a dispersion), a step of aggregating the resin particles (other particles as necessary) to form aggregated particles (aggregated particle forming step), and heating the aggregated particle dispersion in which the aggregated particles are dispersed. And a step of fusing and coalescing the aggregated particles to form toner particles (fusing / coalescing step), thereby producing toner particles.

  In this embodiment, a dispersion in which at least a mixture of the specific squarylium-croconium compound is dispersed is used as the other particle dispersion.

Hereinafter, details of each step will be described.
In the following description, a method for obtaining toner particles containing a colorant and a release agent will be described, but the colorant and the release agent are used as needed. Of course, other additives other than the colorant and the release agent may be used.

-Resin particle dispersion preparation process-
First, a resin particle dispersion in which resin particles serving as a binder resin are dispersed, and a specific squarylium-croconium-based compound dispersion in which a mixture of the specific squarylium-croconium-based compound is dispersed, for example, colorant particles are dispersed. The prepared colorant particle dispersion and the release agent particle dispersion in which the release agent particles are dispersed are prepared.

  Here, the resin particle dispersion is prepared, for example, by dispersing resin particles in a dispersion medium with a surfactant.

Examples of the dispersion medium used for the resin particle dispersion include an aqueous medium.
Examples of the aqueous medium include water such as distilled water and ion-exchanged water, and alcohols. These may be used alone or in combination of two or more.

Examples of the surfactant include anionic surfactants such as sulfate ester type, sulfonate type, phosphate ester type and soap type; cationic surfactants such as amine salt type and quaternary ammonium salt type; polyethylene glycol And non-ionic surfactants such as alkylphenol ethylene oxide adducts and polyhydric alcohols. Among these, anionic surfactants and cationic surfactants are particularly mentioned. The nonionic surfactant may be used in combination with an anionic surfactant or a cationic surfactant.
One type of surfactant may be used alone, or two or more types may be used in combination.

Examples of the method for dispersing the resin particles in the dispersion medium in the resin particle dispersion include general dispersion methods such as a rotary shearing homogenizer, a ball mill having a medium, a sand mill, and a dyno mill. Depending on the type of the resin particles, the resin particles may be dispersed in the resin particle dispersion using, for example, a phase inversion emulsification method.
The phase inversion emulsification method is a method in which a resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and a base is added to an organic continuous phase (O phase) for neutralization. (W phase), a method of converting the resin from W / O to O / W (so-called phase inversion) to form a discontinuous phase, and dispersing the resin in an aqueous medium in a particulate form. It is.

The volume average particle diameter of the resin particles dispersed in the resin particle dispersion is, for example, preferably from 0.01 μm to 1 μm, more preferably from 0.08 μm to 0.8 μm, and further preferably from 0.1 μm to 0.6 μm. preferable.
The volume average particle size of the resin particles is determined by using a particle size distribution obtained by measurement using a laser diffraction type particle size distribution analyzer (for example, LA-700, manufactured by HORIBA, Ltd.). The volume-average particle size D50v is measured by subtracting the cumulative distribution from the small particle size side with respect to the volume and determining the particle size at which 50% of the total particles are accumulated. In addition, the volume average particle diameter of the particles in other dispersion liquids is measured similarly.

  The content of the resin particles contained in the resin particle dispersion is, for example, preferably from 5% by mass to 50% by mass, and more preferably from 10% by mass to 40% by mass.

  In the same manner as the resin particle dispersion, for example, a specific squarylium-croconium-based compound dispersion, a colorant particle dispersion, and a release agent particle dispersion in which a mixture of the specific squarylium-croconium-based compound is dispersed are also prepared. Is done. That is, regarding the volume average particle diameter of the particles in the resin particle dispersion, the dispersion medium, the dispersion method, and the content of the particles, the specific squarylium-croconium-based compound dispersed in the specific squarylium-croconium-based compound dispersion liquid The same applies to the mixture, the colorant particles dispersed in the colorant particle dispersion, and the release agent particles dispersed in the release agent particle dispersion.

-Aggregated particle formation process-
Next, a specific squarylium / croconium compound dispersion, a colorant particle dispersion, and a release agent particle dispersion are mixed together with the resin particle dispersion.
Then, in the mixed dispersion, the resin particles and the specific squarylium-croconium compound, the colorant particles and the release agent particles are hetero-aggregated, and have a diameter close to the diameter of the intended toner particles. Aggregated particles containing the squarylium-croconium compound, the colorant particles, and the release agent particles are formed.

Specifically, for example, a coagulant is added to the mixed dispersion, the pH of the mixed dispersion is adjusted to acidic (for example, the pH is 2 or more and 5 or less), and if necessary, a dispersion stabilizer is added. By heating to a temperature of the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles −30 ° C. or more and the glass transition temperature −10 ° C. or less), the particles dispersed in the mixed dispersion are aggregated. Form aggregated particles.
In the agglomerated particle forming step, for example, the above-mentioned flocculant is added at room temperature (for example, 25 ° C.) while stirring the mixed dispersion with a rotary shearing homogenizer, and the pH of the mixed dispersion is made acidic (for example, pH 2 to 5). ), And the above-mentioned heating may be performed after adding a dispersion stabilizer as needed.

Examples of the coagulant include a surfactant having a polarity opposite to that of the surfactant used as a dispersant added to the mixed dispersion, an inorganic metal salt, and a divalent or higher valent metal complex. In particular, when a metal complex is used as the aggregating agent, the amount of the surfactant used is reduced, and the charging characteristics are improved.
If necessary, an additive that forms a complex or a similar bond with the metal ion of the flocculant may be used. As this additive, a chelating agent is suitably used.

Examples of the inorganic metal salt include metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; and inorganic salts such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide. And metal salt polymers.
As the chelating agent, a water-soluble chelating agent may be used. Examples of the chelating agent include oxycarboxylic acids such as tartaric acid, citric acid and gluconic acid, iminodiic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA).
The addition amount of the chelating agent is, for example, preferably from 0.01 to 5.0 parts by mass, more preferably from 0.1 to less than 3.0 parts by mass, per 100 parts by mass of the resin particles.

-Fusion and coalescence process-
Next, the aggregated particle dispersion in which the aggregated particles are dispersed is heated, for example, to a temperature equal to or higher than the glass transition temperature of the resin particles (for example, equal to or higher than 10 to 30 ° C. higher than the glass transition temperature of the resin particles). To form toner particles.

Through the above steps, toner particles are obtained.
In addition, after obtaining the aggregated particle dispersion in which the aggregated particles are dispersed, the aggregated particle dispersion and the resin particle dispersion in which the resin particles are dispersed are further mixed, and the resin particles are further added to the surface of the aggregated particles. Coagulating so as to adhere to form second aggregated particles, and heating the second aggregated particle dispersion in which the second aggregated particles are dispersed to fuse and unite the second aggregated particles. And forming a toner particle having a core / shell structure.

Here, after completion of the fusion / coalescing step, the toner particles formed in the solution are subjected to a known washing step, solid-liquid separation step, and drying step to obtain dried toner particles.
In the washing step, it is preferable to sufficiently perform replacement washing with ion-exchanged water from the viewpoint of chargeability. The solid-liquid separation step is not particularly limited, but is preferably performed by suction filtration, pressure filtration, or the like from the viewpoint of productivity. The drying step is not particularly limited, but freeze drying, flash jet drying, fluidized drying, vibration type fluidized drying and the like are preferably performed from the viewpoint of productivity.

  The toner according to the exemplary embodiment is manufactured by, for example, adding and mixing an external additive to the obtained dry toner particles. The mixing may be performed by, for example, a V blender, a Henschel mixer, a Lodige mixer, or the like. Further, if necessary, coarse particles of the toner may be removed using a vibration sieving machine, a wind sieving machine, or the like.

<Electrostatic image developer>
The electrostatic image developer according to the exemplary embodiment contains at least the toner according to the exemplary embodiment.
The electrostatic image developer according to the exemplary embodiment may be a one-component developer containing only the toner according to the exemplary embodiment, or a two-component developer mixed with the toner and a carrier.

The carrier is not particularly limited, and includes known carriers. Examples of the carrier include a coated carrier in which a core resin made of a magnetic powder is coated with a coating resin; a magnetic powder-dispersed carrier in which a magnetic powder is dispersed and blended in a matrix resin; a porous magnetic powder impregnated with a resin; And a resin-impregnated carrier.
Note that the magnetic powder-dispersed carrier and the resin-impregnated carrier may be a carrier obtained by using constituent particles of the carrier as a core material and coating the core particles with a coating resin.

  Examples of the magnetic powder include magnetic metals such as iron, nickel, and cobalt, and magnetic oxides such as ferrite and magnetite.

Examples of the coating resin and the matrix resin include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, and styrene-acrylic acid copolymer. Examples thereof include a polymer, a straight silicone resin containing an organosiloxane bond or a modified product thereof, a fluororesin, a polyester, a polycarbonate, a phenol resin, and an epoxy resin.
Note that the coating resin and the matrix resin may contain other additives such as conductive particles.
Examples of the conductive particles include particles such as metals such as gold, silver and copper, carbon black, titanium oxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

Here, in order to coat the surface of the core material with the coating resin, a method of coating the coating resin with a coating layer forming solution in which various additives are dissolved in an appropriate solvent, if necessary, and the like can be mentioned. The solvent is not particularly limited, and may be selected in consideration of the coating resin to be used, suitability for application, and the like.
Specific resin coating methods include an immersion method in which the core material is immersed in a solution for forming the coating layer, a spray method in which the solution for forming the coating layer is sprayed on the surface of the core material, and a method in which the core material is suspended by flowing air. Examples thereof include a fluidized bed method in which a coating layer forming solution is sprayed, and a kneader coater method in which a carrier core material and a coating layer forming solution are mixed in a kneader coater to remove a solvent.

  The mixing ratio (mass ratio) of the toner and the carrier in the two-component developer is preferably toner: carrier = 1: 100 to 30: 100, and more preferably 3: 100 to 20: 100.

(Application)
The toner according to the exemplary embodiment may be a light fixing toner or a heat fixing toner, and is particularly preferably used as a light fixing toner. Further, the toner according to the exemplary embodiment may be a color toner containing a colorant, or a transparent toner containing no colorant (a so-called invisible toner). Here, the invisible toner is, for example, a toner that forms an image to be decoded (read) using invisible light such as infrared light, and is fixed as a toner image on a recording medium (for example, paper). , Toner that is hardly recognized visually (ideally not recognized at all).
The invisible toner may contain a colorant as long as the amount is not recognized (for example, 1% by mass or less).

  Hereinafter, an example of the image forming apparatus according to the present embodiment will be described, but the present invention is not limited thereto. The main parts shown in the figure will be described, and the description of the other parts will be omitted.

<Image forming apparatus / image forming method>
An image forming apparatus / image forming method according to the present embodiment will be described.
The image forming apparatus according to the present exemplary embodiment includes an image carrier, a charging unit that charges a surface of the image carrier, an electrostatic image forming unit that forms an electrostatic image on the surface of the charged image carrier, and an electrostatic charge. Developing means for containing the image developer and developing the electrostatic image formed on the surface of the image carrier as a toner image with the electrostatic image developer, and a recording medium for storing the toner image formed on the surface of the image carrier And a fixing unit for fixing the toner image transferred to the surface of the recording medium. The electrostatic image developer according to the exemplary embodiment is applied as the electrostatic image developer.

  In the image forming apparatus according to the present embodiment, the charging step of charging the surface of the image holding member, the electrostatic image forming step of forming an electrostatic image on the surface of the charged image holding member, and the electrostatic charge according to the present embodiment A developing step of developing an electrostatic charge image formed on the surface of the image holding member as a toner image with an image developer, and a transferring step of transferring the toner image formed on the surface of the image holding member to the surface of the recording medium, An image forming method (image forming method according to the present embodiment) including a fixing step of fixing the toner image transferred to the surface of the recording medium is performed.

The image forming apparatus according to the present embodiment is an apparatus of a direct transfer system that directly transfers a toner image formed on the surface of an image carrier to a recording medium; An intermediate transfer type device that performs primary transfer on the surface and secondary transfer of the toner image transferred on the surface of the intermediate transfer member to the surface of the recording medium; after the toner image is transferred, the surface of the image carrier before charging is cleaned. Apparatus provided with cleaning means; a well-known image forming apparatus such as an apparatus provided with a charge removing means for irradiating the surface of the image holding member with charge removing light to remove the charge after the transfer of the toner image and before charging is applied.
In the case of an intermediate transfer type apparatus, the transfer unit includes, for example, an intermediate transfer member on which a toner image is transferred on the surface, and a primary transfer for temporarily transferring the toner image formed on the surface of the image holding member to the surface of the intermediate transfer member. And a secondary transfer unit for secondary-transferring the toner image transferred on the surface of the intermediate transfer member to the surface of the recording medium.

  In the image forming apparatus according to the present embodiment, for example, a portion including the developing unit may have a cartridge structure (process cartridge) that is detachably attached to the image forming apparatus. As the process cartridge, for example, a process cartridge provided with a developing unit containing the electrostatic image developer according to the exemplary embodiment is preferably used.

  In the image forming apparatus and the image forming method according to the present embodiment, the fixing of the toner image to the recording medium is preferably performed by light fixing by light irradiation. In addition, pressure fixing using a heating member and light fixing by light irradiation may be used in combination.

As a fixing unit for adopting an optical fixing method for irradiating a toner image with light to fix the image, any device that performs fixing by light may be used, and an optical fixing device (flash fixing device) is used.
Examples of the light source used in the optical fixing device include ordinary halogen lamps, mercury lamps, flash lamps, and infrared lasers.

As the heating member, a heating roll fixing device, an oven fixing device, or the like is desirably used.
As the heating roll fixing device, generally, a heating roll type fixing device in which a pair of fixing rolls are pressed against each other is used. In the pair of fixing rolls, for example, a heating roll and a pressure roll are provided to face each other, and a nip is formed by pressing. The heating roll is composed of a metal hollow core having a heater lamp inside, and an oil-resistant and heat-resistant elastic layer (elastic layer) and a surface layer made of a fluororesin are sequentially formed. Accordingly, an oil-resistant and heat-resistant elastic layer and a surface layer are sequentially formed on a metal hollow core having a heater lamp therein. The toner image is fixed by passing the recording medium on which the toner image has been formed through the nip region formed by the heating roll and the pressure roll.

Among these, as the fixing means, an apparatus that irradiates an infrared laser that irradiates a laser beam of 800 nm or more is preferable. This infrared laser is excellent in energy conversion efficiency, that is, luminous efficiency, and easily reduces the energy required for the fixing unit.
Also, the specific squarylium-croconium compound has a maximum absorption wavelength in the wavelength region of 800 nm or more, the absorption efficiency of the infrared laser light by the infrared absorber is improved, and the infrared absorption added to the toner is improved. It becomes easy to reduce the addition amount of the agent.

  FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present embodiment. The image forming apparatus shown in FIG. 1 forms a toner image using toner obtained by adding black to three colors of cyan, magenta, and yellow.

  The image forming apparatus shown in FIG. 1 is configured to feed a recording medium P wound in a roll form by a paper feed roller 328, and on one side of the recording medium P fed in this way, the recording medium P is upstream in the feeding direction. Four image forming units 312 (black (K), yellow (Y), magenta (M), and cyan (C)) are provided in parallel from the side to the downstream side. An optical fixing type fixing device 326 is provided on the downstream side.

The black image forming unit 312K is a known electrophotographic image forming unit. Specifically, a charger 316K, an exposure unit 318K, a developing unit 320K, and a cleaner 322K are provided around the photoconductor 314K, and a transfer unit 324K is provided via the recording medium P. The same applies to the other image forming units for yellow, magenta, and cyan 312Y, 312M, and 312C.
When used for monochrome printing, only black (K) may be provided as the image forming unit 312.

  In the image forming apparatus shown in FIG. 1, a toner image is sequentially transferred by a known electrophotographic method by each of the image forming units 312K, 312Y, 312M, and 312C onto the recording medium P pulled out from the roll state, and The image is optically fixed by the fixing device 326 to form an image. At a position where the fixing device 326 is installed, a pair of heating rolls (not shown) for fixing the toner image to the recording medium P by pressing and heating the recording medium P with the recording medium P interposed therebetween may be provided. By providing a heating device such as a heater in the roll, the heating roll pair is heated, and the toner image is melted and fixed on the recording medium P by the toner image coming into contact with the heating roll pair.

<Process cartridge / Toner cartridge>
The process cartridge according to the present embodiment will be described.
The process cartridge according to the exemplary embodiment stores the electrostatic image developer according to the exemplary embodiment, and develops the electrostatic image formed on the surface of the image holding member as a toner image by the electrostatic image developer. And a process cartridge detachably attached to the image forming apparatus.

  The process cartridge according to the exemplary embodiment is not limited to the above-described configuration, and may include a developing device and other units such as an image holding member, a charging unit, an electrostatic image forming unit, and a transfer unit as needed. And at least one selected from the group consisting of:

Next, the toner cartridge according to the present embodiment will be described.
The toner cartridge according to the present embodiment is a toner cartridge that contains the toner according to the present embodiment and is attached to and detached from the image forming apparatus. The toner cartridge stores toner for replenishment to be supplied to a developing unit provided in the image forming apparatus.

  Note that the image forming apparatus shown in FIG. 1 is an image forming apparatus having a configuration in which a toner cartridge (not shown) is attached and detached, and the developing devices 320K, 320Y, 320M, and 320C correspond to each developing device (color). And a toner supply pipe (not shown). When the amount of toner stored in the toner cartridge becomes low, the toner cartridge is replaced.

  Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited thereto. Unless otherwise specified, “parts” and “%” are based on mass.

<Synthesis of infrared absorber>
[Comparative Example 1]
-Synthesis of infrared absorber (A1a) An infrared absorber (A1a) (compound (A1a) alone) was synthesized according to the following scheme.
2,2,8,8-Tetramethyl-3,6-nonadin-5-ol, cyclohexane, and manganese (IV) oxide were added to a three-necked flask, and heated under stirring. Water formed during the reaction was removed azeotropically. After completion of the reaction, the reaction solution was cooled, and the reaction solution was filtered under reduced pressure and sufficiently washed with ethyl acetate. The filtrate was concentrated under reduced pressure to obtain pale yellow intermediate 1.

  Sodium hydrogen monosulfide n-hydrate was dissolved in ethanol in a three-neck flask. A mixed solution of Intermediate 1 and ethanol was added dropwise at an internal temperature in the range of 5 ° C to 7 ° C. After stirring at 20 ° C., water was added to the reaction solution, and ethanol was removed by distillation under reduced pressure. Thereafter, sodium chloride was added until saturation, and the mixture was extracted with ethyl acetate. The organic phase was washed with saturated ammonium chloride and concentrated under reduced pressure. The residue was distilled under reduced pressure to obtain a yellow liquid of Intermediate 2a.

  Under a nitrogen atmosphere, the intermediate 2a and tetrahydrofuran were added to a three-necked flask, and a 1M solution of methylmagnesium bromide in tetrahydrofuran was added dropwise. The reaction was heated to reflux. After the completion of the reaction, the mixture was cooled to 5 ° C., and an aqueous solution of ammonium bromide was added dropwise. Extraction with ethyl acetate and concentration under reduced pressure gave Intermediate 3a.

  Intermediate 3a, squaric acid, cyclohexane, isobutanol, and pyridine were added to a three-necked flask, and the mixture was heated to reflux. Water generated during the reaction was removed azeotropically. After completion of the reaction, the mixture was filtered under reduced pressure, and the filtrate was concentrated under reduced pressure. The residue was recrystallized from methanol to obtain a compound (A1a). This was designated as an infrared absorbent (A1a).

[Comparative Example 2]
-Synthesis of infrared absorber (A1c) An infrared absorber (A1c) (compound (A1c) alone) was synthesized according to the following scheme.
In a three-neck flask, Intermediate 1 obtained above was dissolved in methanol, and p-toluenesulfonic acid was added. The mixture was heated to reflux. After completion of the reaction, methanol was removed by distillation under reduced pressure. The mixture was diluted with ethyl acetate, washed with water and saturated aqueous sodium hydrogen carbonate, and concentrated under reduced pressure. The residue was distilled under reduced pressure to obtain a yellow liquid intermediate 2c.

  Under a nitrogen atmosphere, the intermediate 2c and tetrahydrofuran were added to a three-neck flask, and a 1M solution of methylmagnesium bromide in tetrahydrofuran was added dropwise. The reaction was heated to reflux. After completion of the reaction, the mixture was cooled to 5 ° C., and an aqueous solution of ammonium bromide was added dropwise. Extraction with ethyl acetate and concentration under reduced pressure gave Intermediate 3c.

  Intermediate 3c, squaric acid, cyclohexane, isobutanol, and pyridine were added to a three-necked flask, and the mixture was heated to reflux. Water generated during the reaction was removed azeotropically. After completion of the reaction, the mixture was filtered under reduced pressure, and the filtrate was concentrated under reduced pressure. The residue was recrystallized from methanol to obtain a compound (A1c). This was designated as an infrared absorbent (A1c).

[Example 1]
-Synthesis of infrared absorber (A1-1) An infrared absorber (A1-1) (a mixture of the compound (A1a) and the compound (A1b)) was synthesized according to the following scheme.
The intermediates 3a and 3c were added to the three-necked flask at the ratios shown in Table 1 below, and squaric acid, cyclohexane, isobutanol, and pyridine were added, and the mixture was heated to reflux. Water generated during the reaction was removed azeotropically. After completion of the reaction, the mixture was filtered under reduced pressure, and the filtrate was concentrated under reduced pressure. The residue was recrystallized from methanol to obtain a mixture containing the compound (A1a) as a main component and the remainder as a compound (A1b). This is designated as an infrared absorbent (A1-1).

  The composition ratio (mass ratio) was measured and confirmed by high performance liquid chromatography (HPLC) according to the method described above. Compound (A1a) was 99.0%, compound (A1b) was 1.0%, and compound (A1c) was below the detection limit.

[Examples 2 to 5]
-Synthesis of infrared absorbers (A1-2) to (A1-5) In the synthesis of the infrared absorber (A1-1), the ratios of the intermediates 3a and 3c were changed to the ratios shown in Table 1 below. Except for the above, infrared absorbers (A1-2) to (A1-5) (mixture of compound (A1a) and compound (A1b)) were obtained in the same manner.

[Example 6]
Preparation of Infrared Absorber (A1-6) Compound (A1a) obtained by synthesizing the aforementioned infrared absorber (A1a) and compound (A1c) obtained by synthesizing the aforementioned infrared absorber (A1c) , 97.0: 3.0 (mass ratio) to obtain a mixture containing the compound (A1a) as the main component and the remainder as the compound (A1c). This is designated as an infrared absorbent (A1-6).

<Synthesis of resin composition>
(Synthesis of polyester resin A)
-Bisphenol A bis (2-hydroxyethyl) ether: 347 parts-Ethylene glycol: 68 parts-Terephthalic acid: 166 parts-Isophthalic acid: 166 parts-Tetrabutoxytitanate (catalyst): 2 parts The flask was placed in a flask, and nitrogen gas was introduced into the vessel to maintain an inert atmosphere and the temperature was raised while stirring. Thereafter, a copolycondensation reaction was performed at 210 ° C. for 7 hours, the temperature was raised to 230 ° C. while gradually reducing the pressure to 1333 Pa, and the temperature was maintained for 8 hours. The acid value was 10.0 mgKOH / g, the weight average molecular weight was 13,000, and the glass transition temperature was Resin A at 62 ° C. was obtained.
The number average molecular weight (Mn) of the obtained polyester resin A was 5,100.

(Preparation of resin composition dispersion)
0.080 g, 0.099 g, and 0.120 g of the tetrahydrofuran solution (concentration: 0.20% by mass) of the infrared absorbent (A1a) obtained above were weighed, and a tetrahydrofuran solution of the polyester resin A (concentration: 35.0%) was used. 5% by mass) to prepare 0.140 g of three kinds of infrared absorbent solutions having different concentrations.
In addition, three types of infrared absorbent solutions having different concentrations were similarly prepared for the infrared absorbents (A1c) and (A1-1) to (A1-6) obtained above.
Each solution was added dropwise to 9.7 g of a 0.05% by mass aqueous potassium carbonate solution stirred with Ultra Turrax (manufactured by Squid Japan) to obtain a resin composition dispersion of an infrared absorbent and a polyester resin A. . The volume average particle size of each of the dispersions was 120 nm.

(Preparation of latex patch)
Using a glass filter having an inner diameter of 36 mm, the resin composition dispersion was filtered through an MF-Millipore membrane filter (paper, manufactured by Merck, model number VMWP) having a pore diameter of 50 nm, and dried and thermally pressed (120 ° C.). A latex patch was prepared.

<Evaluation>
[Reflection spectrum]
The reflection spectrum of the latex patch obtained above was measured with a spectrophotometer U-4100 manufactured by Hitachi, Ltd., and the infrared absorption rate at the infrared absorption peak of the latex patch was obtained.
Note that the infrared absorption peak refers to the infrared absorption peak (820 nm) of the compound (A1a), which is the main component, of the infrared absorber (A1a) and (A1-1) to (A1-6). (A1c) indicates the infrared absorption peak of the compound (A1c), which is the main component, at 720 nm.

[Color difference]
Next, the color difference of the obtained image was measured as follows, and the color turbidity was evaluated.
Note that the color difference (ΔE) is called color difference in the CIE1976L ^* a ^* b ^* color system. The color difference (ΔE) between the recording medium (the MF-Millipore membrane filter (model number VMWP) in this embodiment) and the color difference (ΔE) obtained by measurement using a reflection spectral densitometer (x-rite 939, manufactured by X-Rite Co., Ltd.). , A and b were calculated by the following equations.
Color difference ΔE = ((L ₁ −L ₂ ) ² + (a ₁ −a ₂ ) ² + (b ₁ −b ₂ ) ² ) ^1/2
Here, L ₁ , a ₁ , and b ₁ indicate the L value, a value, and b value of the recording medium surface before the preparation of the latex patch. L ₂ , a ₂ , and b ₂ represent the L value, a value, and b value in the image area (resin composition part) when a latex patch was prepared.
The color difference (ΔE) indicates that the smaller the value is, the harder it is to be visually recognized, that is, the color turbidity is suppressed.

  From the measured values of ΔE of each latex patch made of three types of infrared absorbent solutions having different concentrations, ΔE at which the infrared absorptivity was equivalent to 80% was calculated. The results are shown in Table 1 below together with the content (% by mass) of the infrared absorbent in the resin composition when the infrared absorption is equivalent to 80%.

[Comparative Example 3]
-Synthesis of infrared absorber (B1a) In the synthesis of infrared absorber (A1a) in Comparative Example 1, 2,2,8,8-tetramethyl-3,6-nonadiyne-5 used for synthesis of intermediate 1 -Ol is changed to 5,8-tridecadin-7-ol (that is, the compound b below), whereby the two substituents substituted on the benzene ring in the intermediate 3a are changed from a tert-butyl group to an n-butyl group. Intermediate 4a was synthesized. Next, the following compound (B1a) was obtained using this intermediate 4a. This was designated as an infrared absorbent (B1a).

[Examples 7 and 8]
-Synthesis of infrared absorbers (B1-1) to (B1-2) In the synthesis of infrared absorber (A1c) in Comparative Example 2, 2,2,8,8-tetramethyl used for synthesis of intermediate 1 By changing -3,6-nonadiyn-5-ol to 5,8-tridecadin-7-ol (that is, the following compound b), the two substituents substituted on the benzene ring in the intermediate 3c are tert-butyl. Intermediate 4c in which the group was changed to an n-butyl group was synthesized.

  Next, in the synthesis of the infrared absorber (A1-1) in Example 1, the intermediates 3a and 3c were changed to the intermediates 4a and 4c obtained above, and the intermediates 4a and 4c were obtained. Infrared absorbers (B1-1) to (B1-2) (mixture of compound (B1a) and compound (B1b)) were obtained in the same manner except that the ratio of 4c was changed to the ratio shown in Table 2 below. .

  Also in Comparative Example 3 and Examples 7 and 8, a resin composition dispersion liquid was prepared and evaluated in the same manner as in Example 1.

From the results shown in Table 1, Examples 1 to 5 using the infrared absorbers (A1-1) to (A1-5), which are a mixture of the compounds (A1a) and (A1b), and the compounds (A1a) and (A1c) In Example 6 using the infrared absorbent (A1-6) which is a mixture of (1), the color difference was higher than Comparative Example 1 using the infrared absorbent (A1a) and Comparative Example 2 using the infrared absorbent (A1c). It can be seen that the value of ΔE is low, and the color turbidity is suppressed.
Also, from the results shown in Table 2, in Examples 7 and 8 using the infrared absorbers (B1-1) to (B1-2), which are a mixture of the compounds (B1a) and (B1b), the infrared absorber (B1a) was used. ) Shows that the value of the color difference ΔE is lower than that of Comparative Example 3 in which the color turbidity is suppressed.

312Y, 312M, 312C, 312K Image forming units 314Y, 314M, 314C, 314K Photoconductors 316Y, 316M, 316C, 316K Chargers 318Y, 318M, 318C, 318K Exposure means 320Y, 320M, 320C, 320K Developers 322Y, 322M, 322C, 322K Cleaner 324Y, 324M, 324C, 324K Transfer device 326 Fixing device 328 Paper feed roller P Recording medium

Claims (8)

Resin and
At least one selected from the group consisting of compounds represented by the following general formula (I-1),
At least one selected from the group consisting of a compound represented by the following general formula (I-2) and a compound represented by the following general formula (I-3),
Only including,
Among the compound represented by the general formula (I-1), the compound represented by the general formula (I-2), and the compound represented by the general formula (I-3), the compound represented by the general formula (I-1) ) The proportion of the compound represented by the formula (I) or the proportion of the compound represented by the formula (I-2) is from 85.0% by mass to 99.9% by mass .

(In the general formula (I-1), the general formula (I-2) and the general formula (I-3), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ²¹ , R ²² , R ²³ , R ²⁴ , R ³¹ , R ³² , R ³³ , and R ³⁴ each independently represent hydrogen, an alkyl group, an alkoxy group, an aryl group, or an aralkyl group, R ¹⁵ , R ¹⁶ , R ²⁵ , R ²⁶ , R ³⁵ , And R ³⁶ each independently represent hydrogen or an alkyl group, X represents oxygen, sulfur, selenium, or tellurium, a plurality of Xs represent the same element, and Y represents oxygen, sulfur, selenium. Or tellurium, and represents an element different from X, and a plurality of Y represents the same element, wherein A ¹ , A ² , and A ³ are each independently the general formula (a1) or the general formula (a1); Represents a divalent group represented by the formula (a2). A divalent group represented by (a1) or the general formula (a2) is attached at *.)   The X in the general formula (I-1), the general formula (I-2) and the general formula (I-3) represents one of oxygen and sulfur, and the Y represents the other of oxygen and sulfur. The resin composition as described in the above. An electrostatic image developing toner comprising the resin composition according to claim 1 . An electrostatic image developer comprising the electrostatic image developing toner according to claim 3 . A toner for developing an electrostatic image according to claim 3 ,
A toner cartridge that is attached to and detached from an image forming apparatus. A developing unit which contains the electrostatic image developer according to claim 4 and develops the electrostatic image formed on the surface of the image holding member as a toner image by the electrostatic image developer,
A process cartridge that is attached to and detached from the image forming apparatus. An image carrier,
Charging means for charging the surface of the image holding member,
Electrostatic image forming means for forming an electrostatic image on the surface of the charged image carrier,
A developing unit that stores the electrostatic image developer according to claim 4 and develops the electrostatic image formed on the surface of the image holding member as a toner image by the electrostatic image developer;
Transfer means for transferring the toner image formed on the surface of the image carrier to the surface of the recording medium,
Fixing means for fixing the toner image transferred to the surface of the recording medium,
An image forming apparatus comprising: A charging step of charging the surface of the image carrier,
An electrostatic image forming step of forming an electrostatic image on the surface of the charged image carrier,
A developing step of developing the electrostatic image formed on the surface of the image holding member as a toner image with the electrostatic image developer according to claim 4 ;
A transfer step of transferring the toner image formed on the surface of the image carrier to the surface of a recording medium,
Fixing step of fixing the toner image transferred to the surface of the recording medium,
An image forming method comprising: